Vascular Access Devices (VADs) are commonly used therapeutic devices and include intravenous catheters, syringes, extension sets, stop cocks, tubing, high pressure extension tubing, and needleless access devices. The operation of VADs is often compromised or completely prevented by the occurrence of thrombus formation. Thrombosis is the development of a blood clot within a vessel and/or vascular access device. If not properly maintained, VADs can become occluded. To ensure VADs are used properly and do not become occluded, standards of practice have been developed. These standards include a cleaning procedure, which is commonly referred to as a flush procedure. The purpose of flushing is to clean the accumulated residue from dead-space located between male and female luer connections. The common flushing practice creates a turbulent flow during flushing to promote a “scrubbing” effect in the lumen and at the tip of the catheter.
VAD standards of practice usually recommend that flush procedures be performed after catheter placement, before fluid infusion, and before and after drug administration, blood sampling, transfusions and parenteral nutrition. The goal of these flush procedures is to confirm catheter patency, avoid drug incompatibilities, ensure complete drug dose administration, prevent thrombus formation and minimize the risk of blood stream infections. Flush procedures require different types and amounts of flush solutions. The most commonly used flush solutions are saline and/or heparin lock solution. The type of flush solution and amount vary depending on the specific type of catheter. Flush solution volumes between 5 and 10 ml are most common but can range from 1 ml to 20 ml.
One form of VAD maintenance typically used includes a continuous saline drip where a saline bag is connected to the VAD and provides continuous flow of saline solution to the patient through the VAD. This approach may put the patient at risk by delivering excess fluid to the vascular space. An alternative method for vascular device maintenance, known as flushing, involves intermittent delivery of saline through the VAD using a hypodermic syringe.
The effectiveness of the flushing procedure in intravenous therapy is related to the risk of microbial colonization and potential Catheter Related Bloodstream Infection (CRBSI). Thus, the greater the amount of blood and residue remaining in the catheter system, the higher the risk for infection and complications related to infection.